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Citation:

Hu FB, van Dam RM, Liu S. Diet and risk of Type II diabetes: The role of types of fat and carbohydrate. Diabetologia. 2001 Jul; 44(7): 805-817.


PubMed ID: 11508264
Study Design:
Meta-analysis or Systematic Review
Class:
M - Click here for explanation of classification scheme.
POSITIVE: See Research Design and Implementation Criteria Checklist below.
Research Purpose:

To review current evidence on the association between types of fat and carbohydrate and insulin resistance and T2D (T2D).

Inclusion Criteria:
  • Epidemiologic studies that examine the associations between dietary fat and carbohydrate and risk of developing hyperglycemia and T2D
  • Included both prospective cohort studies and cross-sectional studies
  • Examined specific fatty acids
  • Subjects without T2D or IGT (IGT).
Exclusion Criteria:
  • Human diet intervention trials
  • Did not examine specific fatty acids
  • Subjects with T2D or IGT
  • Animal studies.
Description of Study Protocol:

Recruitment

14 epidemiologic studies and five cross-sectional studies of dietary fat and carbohydrate and association with hyperglycemia and T2D.

Design 

systematic review

Dietary Intake/Dietary Assessment Methodology

Food-frequency questionnaires (FFQs) and diet history.

 

 

Data Collection Summary:

Date Range

1974 to 2001.

Dependent Variables 

T2D.

Independent Variables 

Types of dietary fatty acids and carbohydrate.

 

Description of Actual Data Sample:
  • Initial N: 20 to 4,903
  • Age: Adults (age range 25 to 89 years)
  • Ethnicity: International
  • Other relevant demographics: Observational studies conducted on men and women in specific sub-populations in the US, Europe and Israel
  • Location: US, Europe, Israel.
Summary of Results:

 Key Findings

  • Higher intakes of polyunsaturated fatty acid (PUFA) could improve glucose metabolism and insulin resistance
  • Long-chain PUFA may also improve glucose metabolism and insulin resistance
  • Higher intakes of saturated fatty acid (SFA) adversely affect glucose metabolism and insulin resistance
  • High intakes of vegetable fat and PUFA were associated with a decreased risk of T2D.

 

Author Conclusion:

Replacing SFA with PUFA could appreciably reduce risk of T2D.

Reviewer Comments:

None.


Research Design and Implementation Criteria Checklist: Review Articles
Relevance Questions
  1. Will the answer if true, have a direct bearing on the health of patients?
Yes
  2. Is the outcome or topic something that patients/clients/population groups would care about?
Yes
  3. Is the problem addressed in the review one that is relevant to nutrition or dietetics practice?
Yes
  4. Will the information, if true, require a change in practice?
Yes
 
Validity Questions
  1. Was the question for the review clearly focused and appropriate?
Yes
  2. Was the search strategy used to locate relevant studies comprehensive? Were the databases searched and the search termsused described?
Yes
  3. Were explicit methods used to select studies to include in the review? Were inclusion/exclusion criteria specified and appropriate? Were selection methods unbiased?
Yes
  4. Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methods specified, appropriate, and reproducible?
???
  5. Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined?
Yes
  6. Was the outcome of interest clearly indicated? Were other potential harms and benefits considered?
Yes
  7. Were processes for data abstraction, synthesis, and analysis described? Were they applied consistently across studies and groups? Was there appropriate use of qualitative and/or quantitative synthesis? Was variation in findings among studies analyzed? Were heterogeneity issued considered? If data from studies were aggregated for meta-analysis, was the procedure described?
Yes
  8. Are the results clearly presented in narrative and/or quantitative terms? If summary statistics are used, are levels of significance and/or confidence intervals included?
Yes
  9. Are conclusions supported by results with biases and limitations taken into consideration? Are limitations of the review identified and discussed?
Yes
  10. Was bias due to the review’s funding or sponsorship unlikely?
Yes